There's also the other end of the spectrum, where lossless codecs (apple or FLAC or...) can be used to minimise disk I/O (say 60% of uncompressed) with no loss of fidelity and a generally affordable CPU overhead
and to shamelessly plug our stuff again :)
We have posted FLAC versions of Audio Codecs on their web site - so this format (file and data) can be used with the rest of the core audio API set (including all of the stuff around priming and remainder frames). Any of these formats - flac, apple lossless, etc... - can be put into a CAF file, so one file format can be used to carry around any of these codecs, and the format clearly describes the meta data you need to do this kind of thing. We also support apple lossless on iphone/ipod touch as well of course.
On Feb 11, 2009, at 8:33 PM, Marco Papa wrote: Indeed that would be my tradeoff, though the majority of stuff on the AppStore now is games, and very few are "small".
On Wed, Feb 11, 2009 at 8:18 PM, Jens Alfke <email@hidden> wrote: On Feb 11, 2009, at 7:54 PM, Marco Papa wrote: Fabulous explanation, Bill. Now, wouldn't juts avoid all these issues if I were to use uncompressed audio, like your last wave file, with AVAudioPlayer, for example? Sure. It's just going to be about 10x larger on disk/flash than compressed audio, and use 10x the I/O bandwidth to play back (though less CPU). It's up to you whether your product can live with that. Developers usually try to keep iPhone apps pretty small, to make it feasible for customers to download them over EDGE. —Jens
-- Marco Papa, Ph.D. Computer Science Department University of Southern California Henry Salvatori Computer Center Los Angeles, California 90089-0781 Voice: +1-213-974-2137 Cell: +1-310-944-5468 E-mail: email@hidden
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